Acoustic material



y 1941- c. A. SLECHTAY- 2,250,683

ACOUSTIC MATERIAL Filed Jan. 22, 1937' 2' Sheets-Sheet 1 INVENTOR. CYR/L. A. SLECHTH ATTORNEY Patented July 29, 1941 UNITED STTS rice ACOUSTIC 'MATERIAL Cyril A. Slechta, St. Paul, Minn.

Application January 22, 1937', Serial No. 121,842

(Cl. M L-44) 4 Claims.

This invention relates to an acoustic material or product for sound absorbing or deadening purposes.

An object of the invention is to provide an acoustic material orp'roduct which will include channels, passageways or apertures extending completely and/ or partially through the material edgewise, or approximately parallel to a sound receiving surface, or surfaces, of said material, and which channels, passageways or apertures will be adapted to collect sound waves and cause them to be absorbed or smothered and thus expunged.

A further object is to provide an acoustic material or product which will in practice absorb or deaden sound in uniform manner over substantially the whole of the sound receiving surface of the material or product.

A further object is to provide an acoustic material or product which will :include internal channels, passageways or apertures and will be designed and constructed with the end in view of accomplishing substantially uniform absorption or deadening of sound throughout an entire sound range. V

A further object is to provide an acoustic material or product which will include duplicate sound absorbing or deadening areas each having internal channels, passageways or apertures and which sound absorbing or deadening areas will together render the material or productcapable of substantially uniformly absorbing or deadening sound over the whole of the sound receiving surface of said material or product. 7 And a further object is to provide an acoustic material or product wherein will be incorporated various improved features and characteristics of construction novel both as individual entities of the material or product and in combination with each other.

With the above objects in view, as well'as details of construction and arrangement of parts being permissible so long as within the spirit of the invention and the scope of the claims which, follow. v p

In the accompanying drawings forming a part of this specification,

Fig. 1 is an elevational edge view of an acoustic material structure made according to the invention; I

Fig. 2 is an elevational top or front plan view of the structure of Fig. 1;

Fig. 3 is an elevational bottom plan view of the upper element of the structure of Figs; 1 and 2;

Fig. 4 is an elevational top plan view of the lower element of the structure of Figs. 1 and 2;

Fig. 5 is an elevational top or front plan view of an acoustic material structure of modified construction made according to the invention;

Fig. 6 is an elevational edge view of the structure of Fig. 5;

Figs. 7 to 12 are elevational top or front plan views of acoustic material structures of variant constructions made according to the invention; and

Fig. 13 is an elevational edge view of the struc- In thefinishedmaterial or product the meeting surfaces IT; IS are parallel with the flat outer or front surface IQ of the element It: and the flat outer or rear surface 20 of the element l6, and said meeting surfaces l1 and I8 may be at equal a I distance from the surfaces I9 and 20. Also, the side and end portions of the plank or board are bevel-ed, as indicated at 2|, and said plank or board includes channels, passageways or apertures 22, equally spaced apart as disclosed, which extend edgewise, some completely and some partially, through the material or product. Some of the channels, passageways or apertures 22 are shown as circular and some are shown as square in cross section to illustrate that said channels,

passageways or apertures can be of any desired or preferred configuration. All of the channels,

passageways or apertures are at the elevation of thesurfaces I1 and I8 and are parallel with thesurfaces 59 andfll. The flat outer or front surface I9 of the element l5 includes longitudinally extending grooves 23 merely for decorative P lI Q The manner in which the acoustic material structure of Figs. 1 and 2 is manufactured will be clear from Figs. 3 and 4. Each element 15 and I6 is separately made and said elements are afterwards glued or otherwise secured to each other so that bevels of the different elements cooperate to provide the bevels 2|, as will be understood. The channels, passageways or apertures 22 are as disclosed partially in the element l5 and partially in the element l6. That is, in the manufacture of each element l5, IS, the element is provided with spaced apart grooves or ruts which are to provide longitudinal halves or parts of the channels, passageways or apertures 22, and the arrangement is such that when the different elements l5 and iii are secured together each groove or rut of each element is complemental to a groove or rut of the other element to provide therewith one of said channels, passageways or apertures 22.

The acoustic material structure of Figs. 1 and 2 may be composed of any substance usable for sound absorbing or deadening effect. It will be obvious that especially insofar as the production of the channels, passageways or apertures 22 is concerned there is a distinct manufacturing advantage in partially providing said channels, passageways or apertures in each of separate pieces of material and producing the completed channels, passageways or apertures by union of said pieces of material. The job is greatly simplified no matter how the particular substance employed directs that the channels, passageways or apertures be formed, by casting, by reaming, or other- Wise.

As very clearly disclosed, the opposite ends of each channel, passageway or aperture 22 which passes through the plank or board are disposed in or at the side bevels 2i, and the outer end of each channel, passageway or aperture 22 which passes partially through said plank or board is disposed in or at a side bevel. The acoustic material structure will ordinarily be installed so that the sound absorbing or deadening surface thereof is exposed as illustrated in the elevation'al front plan view of Fig. 2. A considerable number of sound waves which strike the material will enter the channels, passageways or apertures at their open ends, and a still greater number of sound waves will enter said channels, passage- Ways or apertures by passing directly through the substance of said material. In both instances the channels, passageways or apertures will effectively smother or absorb the sound in well known manner.

Attention is called to the fact that the channels, passageways or apertures 22 are in rather close proximity to the sound receiving surface l9 so that the sound waves will encounter little difficulty in reaching said channels, passageways or apertures by travel directly through the material or substance of the acoustic product.

It will be apparent that the channels, passageways or apertures 22 divide the acoustic material or product into duplicate, regularly recurring sound absorbing or deadening areas which will together render the material or product capable of substantially uniformly absorbing or deadenme sound over the whole of the sound receiving surface of said material or product and throughout an entire sound range. That is, the acoustic material or product includes a plurality of duplicate sound absorbing or deadening areas each having capacity for absorption of sound throughout an entire sound range, and there is a regular and uniform recurrence of said duplicate areas tending to make for uniform absorption of sound over the whole of the sound receiving surface of the material or product.

Stated differently, the channels, passageways 0r apertures 22 divide the acoustic material or product into different duplicate sections each constructed by reason of said channels, passageways or apertures to absorb sounds of different pitch throughout a range, and the duplicate sections are uniformly repeated over the sound receiving surface of the material or product. Because of the regularly increasing and decreasing thickness of the different sound absorbing areas or sections, by reason of the channels, passageways or apertures 22, there is considerable absorption of sound at each area or section throughout an entire sound range, and because of the regular and uniform recurrence of duplicate areas or sections there is substantially uniform absorption of sound over the whole of the sound receiving surface of the material or product.

In Figs. 5 and 6 there is disclosed an acoustic material structure 24 generally like the structure as in-Figs. 1 and 2, but consisting of a single piece of material with channels, passageways or apertures 25 of circular configuration in cross section extending the full width of the structure. The acoustic material or product of Figs. 5 and 6 includes bevels 26 at both sides and at one end, and the channels, passageways or apertures 25 open at their opposite ends in or at the side bevels 26. Said channels, passageways or apertures 25 are at equal distance from the forward and rearward surfaces of the plank or board 24 and are parallel with said forward and rearward surfaces and with each other. The general remarks made with respect to the plank or boa-rd of Figs. 1 and 2 apply as well to the plank or board of Figs. 5 and 6.

Figs. 7 to 13 disclose an acoustic material structure including features of the invention and made in the shape of tile. As illustrated, each tile structure is a single piece, although the tile could be constructed as in Figs. 1 to 4.

In Fig. 7 the channels. passageways or apertures 21 extend across the tile in two different directions at right angles to each other, and the ends of said channels, passageways or apertures terminate in or at the bevels 28.

In Fig. 8 the channels, passageways or apertures 29 extend across the tile in one direction only, and the ends of said channels, passageways or apertures terminate in or at the bevels 3D.

In Fig. 9 the channels, passageways or apertures 3| extend only partially inwardly from the bevels 32.

Fig. 10 shows channels, passageways or apertures 33 as in Fig. 8 and channels, passageways or apertures 34 as in Fig. 9.

Fig. 11 shows channels, passageways or apertures 35 as in Fig. 8, and decorative grooves 36.

Figs. 12 and 13 show channels, passageways or apertures 31 as in Fig. 7, and decorative grooves 38.

The general remarks made with respect to the plank or board of Figs. 1 and 2 also apply to the tile of Figs. 7 to 13.

The acoustic material or product of the invention can, obviously, be set up as plank or board, molding and tile utilized to create a complete finish for walls, as of theaters, auditoriums, schools, homes, etc., and in such manner that each separate unit employed willoffer its own individual acoustic efficiency. The combination of plank or board, molding and tile affords opportunity for an unlimited number of patterns and designs of general structure. No passageways from the interior to the exterior of an enclosure are provided.

The finished acoustic product adapts itself to be manufactured from materials too innumerable to be specifically mentioned. The sound Waves are taken up and absorbed by the channels, passageways or apertures, as well as by the internal surface areas created by said channels, passageways or apertures. Due to the close proximity of the hidden channels, passageways or apertures to the sound receiving surfaces of the acoustic material or product, said channels, passageways or apertures are effective in the performance of their functions even though surfaced, veneered, or decorated with paint. The channels, passageways or apertures to a marked degree absorb sound waves which strike the exposed surfaces of the planks or boards, moldings or tile. Acoustic material including the features and characteristics of the invention reduces the sound which can travel either into or out of an enclosure equipped with the material.

An acoustic material or product made according to the invention will have uniform sound absorbing capacity per unit of area. The substance of which the acoustic material utilized in some particular instance is composed, and the construction and arrangement of the channels, passageways or apertures employed, evidently can be selectively predetermined to the production of any acoustic result which may be desired. Installations are independent of the skill of workmen.

Among many advantageous features which the acoustic material or' product of the invention presents, the following may be mentioned. The original cost is very little more than the cost of plank or board, molding and tile installations as now made. A completed installation has particularly attractive appearance. Installation is accomplished in the manner as now in vogue in the installing of planks or boards, moldings, and tile in buildings. The construction permits redecoration without reduction of the acoustic properties of the product as manufactured and installed.

What is claimed is:

1. An acoustic product comprising an element including a substantially flat sound absorbing surface and a surface including grooves opposite said substantially flat surface, and a second element having a surface including grooves secured to the grooved surface of said first mentioned element, said grooves of the different elements complementing each other to provide sound absorbing channels.

2. An acoustic product comprising an element including a substantially fiat sound absorbing surface and a substantially flat surface in parallel, slightly spaced apart relation to the surface first mentioned, there being grooves in said last mentioned surface and substantially parallel with the first mentioned surface, and a second element having a substantially flat surface secured to the grooved surfaceof said element, there being grooves in said mentioned surface of the second element and substantially parallel with the first mentioned surface, said grooves of the different elements complementing each other to provide sound absorbing channels.

3. An acoustic product comprising an element including a substantially flat sound absorbing surface and a substantially fiat surface in parallel, slightly spaced apart relation to the surface first mentioned, there being grooves in said last mentioned surface and substantially parallel with the first mentioned surface, and a second element having a substantially fiat surface secured to the grooved surface of said element, there being grooves in said mentioned surface of the second element substantially parallel with the first mentioned surface, said grooves of the different elements complementing each other to provide sound absorbing channels, said product including beveled edge portions constituted by said elements, and outer edge portions of said channels terminating in said beveled edge portions.

4. An acoustic product comprising a pair of elements each composed of board like material, including an element having a sound absorbing surface and a surface opposite said first mentioned surface in slightly spaced relation thereto and a second element secured to said element, the product including a beveled edge portion constituted by said elements, there being sound absorbing channels between the elements and outer end portions of the channels terminating in the beveled edge portion, and each of said channels consisting of complementary grooves in said different elements of board like material.

CYRIL SLECHTA. 

